The United Nations, which has been supporting the process, has urged Afghans to "use this opportunity to exercise their constitutional right to vote" and called for the election to take place in a safe and secure environment.

Afghan polling staff prepare for voting at a polling station during the Parliamentary election in Kabul, Afghanistan, Saturday, October 20, 2018
(Reuters)

More than 130 Afghans were killed or wounded in poll-related violence on Saturday, officials said, as the legislative election turned chaotic with hundreds of polling centres failing to open and voters queueing for hours.

Most of the casualties were in Kabul. A suicide bomber blew himself up in the Afghan capital on Saturday, killing at least 15 people.

Voting should have been concluded by the time the attacker struck in an area to the north of Kabul, but polling stations were kept open longer than normal to cope with large numbers of people who had been unable to vote.

TRT World'sAli Mustafa has more from Kabul.

Ten civilians and five police officers were killed when the bomber tried to enter a polling station and more than 25 were wounded, a senior security official said.

The attack came after the Taliban warned voters to boycott the ballot "to protect their lives".

The vote has been overshadowed by chaotic organisation, allegations of corruption and violence that has forced a postponement of the vote in the strategic southern province of Kandahar.

The United Nations, which has been supporting the process, has urged Afghans to "use this opportunity to exercise their constitutional right to vote" and called for the election to take place in a safe and secure environment.

Officials worry that violence will keep voters away from polling stations, particularly following the assassination of the police chief of Kandahar on Thursday, which forced authorities to delay the election in the province by a week.

Taliban militants have issued a series of statements telling people not to take part in what they consider a foreign-imposed process and warning election centres may be attacked.

Thousands of police and soldiers have been deployed across the country but already nine candidates have been assassinated and hundreds of people killed and wounded in election-related attacks.

Polls opened at 0230 GMT and voting is due to continue until 1130 GMT.

Due to the difficulty of collecting and collating results across Afghanistan, the overall results will not be known for at least two weeks.

Election authorities originally planned 7,355 polling centres but only 5,100 will be able to open due to security concerns, according to the Independent Election Commission, overseeing the vote.

Voting has also been delayed in Ghazni province, by arguments about the representation of different ethnic groups.

Fraud fears

Widespread allegations of voter fraud present a challenge to the legitimacy of the process, seen by Afghanistan's international partners as a vital step ahead of the more important presidential election next year.

Afghan politics is still poisoned by the aftermath of a disputed presidential vote in 2014 that forced the two main rival groupings to form an unstable partnership. Both sides were accused of massive electoral cheating.

Political sleaze has put Afghanistan near the bottom of Transparency International's world corruption index.

"Fraud, the abuse of power and corruption are going to be the main challenge, much more than security," said Aziz Rafiee, a political analyst and executive director of the Afghan Civil Society Forum.

Some 8.8 million voters have been registered but an unknown number, by some estimates as many as 50 percent or more, are believed to be fraudulently or incorrectly registered.

About 2,450 candidates are competing for places in the lower house, which has 250 seats, including one reserved for a candidate from the Sikh minority. Under the constitution, parliament reviews and ratifies laws but has little real power.

In a bid to ensure the vote is fair, biometric voter registration technology has been rushed in at the last minute.

But many fear the untried technology, which was still being distributed to provincial voting centres as recently as Thursday, will add to the confusion without eliminating fraud.